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Web UI, MQTT & HTTP — DimmerLink Native Tasmota Driver

Web UI usage

Dashboard

Brightness sliders

When one or more DimmerLink devices are detected, the Tasmota main page (http:///) displays a brightness slider for each active channel.

The slider layout is:

  • For a single device, sliders are labeled DL Ch1, DL Ch2, etc.
  • For multiple devices, sliders are labeled DL1 Ch1, DL1 Ch2, DL2 Ch1, etc.

Sliders range from 0 (off) to 100 (full brightness). Dragging the slider and releasing sends a DlDim command to the corresponding channel. The slider reflects the current brightness level stored in the driver and updates when the level changes from any source (command, MQTT, etc.).

Sensor display

The sensor section of the main page shows a read-only status table for each device:

Row label Value shown Example
DimmerLink1 Ch1 Brightness and curve 75% (LOG)
DimmerLink1 Ch2 Brightness and curve 30% (RMS)
DimmerLink1 AC Detected mains frequency 50 Hz
DimmerLink1 Fade Fade time (raw and seconds) 10 (1.0s)
DimmerLink1 Temp Temperature and thermal state 42 C (NORMAL)

The Temp row appears only if the temperature feature is available on the hardware. All rows update on each web page refresh; the sensor section is not a live push feed.

MQTT telemetry

Telemetry publication

The driver contributes to Tasmota's periodic tele//SENSOR message (the FUNC_JSON_APPEND hook). The telemetry interval is controlled by Tasmota's TelePeriod setting (default 300 seconds).

JSON structure — single device

json
{
  "Time": "2026-04-16T12:00:00",
  "DimmerLink1": {
    "Addr": "0x50",
    "ACFreq": 50,
    "Fade": 10,
    "Ch1": {"Level": 75, "Curve": "LOG"},
    "Ch2": {"Level": 30, "Curve": "RMS"},
    "Ch3": {"Level": 0, "Curve": "LINEAR"},
    "Ch4": {"Level": 0, "Curve": "LINEAR"},
    "Temp": 42,
    "Thermal": "NORMAL"
  }
}

JSON structure — multiple devices

When multiple devices are present, all appear as separate keys in the same SENSOR message:

json
{
  "Time": "2026-04-16T12:00:00",
  "DimmerLink1": {
    "Addr": "0x50",
    "ACFreq": 50,
    "Fade": 0,
    "Ch1": {"Level": 75, "Curve": "LINEAR"},
    "Ch2": {"Level": 0, "Curve": "LINEAR"},
    "Ch3": {"Level": 0, "Curve": "LINEAR"},
    "Ch4": {"Level": 0, "Curve": "LINEAR"}
  },
  "DimmerLink2": {
    "Addr": "0x51",
    "ACFreq": 50,
    "Fade": 5,
    "Ch1": {"Level": 50, "Curve": "LOG"},
    "Ch2": {"Level": 0, "Curve": "LINEAR"},
    "Ch3": {"Level": 0, "Curve": "LINEAR"},
    "Ch4": {"Level": 0, "Curve": "LINEAR"}
  }
}

Field descriptions

Field Type Description
Addr string I2C address in hex, e.g. "0x50"
ACFreq integer Detected mains frequency, 50 or 60 Hz
Fade integer Current fade time setting (0-255, units of 100ms)
Ch1 ... Ch4 object Per-channel data
Ch1.Level integer Brightness in percent (0-100)
Ch1.Curve string Dimming curve: "LINEAR", "RMS", or "LOG"
Temp integer Temperature in Celsius (only if hardware supports it)
Thermal string Thermal protection state (only with temperature sensor)

The Temp and Thermal fields are omitted if the MCU firmware does not have FEATURE_TEMPERATURE enabled, or if the temperature register returns 0xFF.

Sending commands via MQTT

Commands are sent to cmnd// with the payload as the argument:

plaintext
Topic:   cmnd/my-device/DlDim
Payload: 75
Topic:   cmnd/my-device/DlDim
Payload: 2,30
Topic:   cmnd/my-device/DlCurve
Payload: 2
Topic:   cmnd/my-device/DlFade
Payload: 10

Command responses are published to stat//RESULT:

json
{"DlDim1":{"Ch1":75,"Ch2":30,"Ch3":0,"Ch4":0}}

HTTP API

All Tasmota commands are accessible via HTTP GET using the /cm endpoint.

Syntax

plaintext
http:///cm?cmnd=%20

The space between command and argument must be URL-encoded as %20.

Examples with curl

bash
# Set device 1, channel 1 to 75%
curl "http://192.168.1.100/cm?cmnd=DlDim%2075"
# Set device 1, channel 2 to 30%
curl "http://192.168.1.100/cm?cmnd=DlDim%202,30"
# Set device 2, channel 1 to 50%
curl "http://192.168.1.100/cm?cmnd=DlDim2%2050"
# Set dimming curve to LOG on channel 1
curl "http://192.168.1.100/cm?cmnd=DlCurve%202"
# Set fade time to 1 second (value 10)
curl "http://192.168.1.100/cm?cmnd=DlFade%2010"
# Query full status of device 1
curl "http://192.168.1.100/cm?cmnd=DlStatus"
# Query full status of device 2
curl "http://192.168.1.100/cm?cmnd=DlStatus2"
# Recalibrate AC frequency on device 1
curl "http://192.168.1.100/cm?cmnd=DlRecalibrate"
# Change device 1 I2C address to 0x51
curl "http://192.168.1.100/cm?cmnd=DlAddress%200x51"

Response format

All responses are JSON, returned with HTTP 200:

json
{"DlDim1":{"Ch1":75,"Ch2":30,"Ch3":0,"Ch4":0}}

Error response (invalid device number, out of range argument, etc.):

json
{"Command":"Error"}
Web UI usage MQTT telemetry HTTP API